Add this to your index.html or js file (I’m assuming you have jQuery here, you could use standard javascript of course.):
<script type="text/javascript">// <![CDATA[
function loading(){
$("#loading").show();
$("#content").hide();
}
// ]]></script>
Add this to you html or css file:
div#loading {
width: 35px;
height: 35px;
display: none;
background: url(/static/loadingimage.gif) no-repeat;
cursor: wait;
}
You can get an adequate GIF from http://www.ajaxload.info/. Download and put it into your static folder.
Then change your submission button to call above js function:
<input type="submit" name="anything_submit" value="Submit" onclick="loading();">
and add in a loading and a content div to you base html file:
<body>
<div id="loading"></div>
<div id="content">
<h3>Type anything:</h3>
<p>
<form action="." method="POST">
<input type="text" name="anything" placeholder="Type anything here">
<input type="submit" name="anything_submit" value="Submit" onclick="loading();">
</form>
</p>
</div>
</body>
Now when you click ‘Submit’, the js function should hide your content and display a loading GIF. This will display until your data is processed and flask loads the new page.